Process for preparing 1-methoxymethyl 5,5-diphenybarbituric acid

Abstract

The present invention provides a novel process for preparing 1-methoxymethyl-5,5-diphenylbarbituric acid. In particular, the present invention provides a process for preparing 1-methoxymethyl-5,5-diphenylbarbituric acid by reacting 1,3-bis(methoxymethyl)-5,5-diphenylbarbituric acid with a Lewis acid to selectively remove one methoxymethyl group from 1,3-bis(methoxymethyl)-5,5-diphenylbarbituric acid.

1 . A process for preparing 1-methoxymethyl-5,5-diphenylbarbituric acid comprising the steps of: 
 (a) reacting 1,3-bis(methoxymethyl)-5,5-diphenylbarbituric acid with about 0.6 equivalent to about 1 equivalent of aluminum chloride, at a temperature of about 70° C. to about 130° C., for about two to about three hours; and    (b) isolating the 1-methoxymethyl-5,5-diphenylbarbituric acid.    
   
   
       2 . The process of  claim 1 , wherein step (a) is performed in chlorobenzene.  
   
   
       3 . The process of  claim 1 , wherein step (b) further comprises the steps of: 
 a′) extracting the 1-methoxymethyl-5,5-diphenylbarbituric acid into an aqueous sodium hydroxide solution;    b′) acidifying the basic aqueous solution to precipitate the extracted 1-methoxymethyl-5,5-diphenylbarbituric acid; and    c′) collecting the precipitated 1-methoxymethyl-5,5-diphenylbarbituric acid.    
   
   
       4 . The process of  claim 1 , further comprising the step of purifying the isolated 1-methoxymethyl-5,5-diphenylbarbituric acid.  
   
   
       5 . The process of  claim 4 , wherein the purifying step is performed by crystallization from ethanol.  
   
   
       6 . The process of  claim 4 , wherein the purifyng step is performed by crystallization from a mixture of methanol and water.  
   
   
       7 . The process of  claim 6 , wherein the purifying step further comprises recrystallization from toluene followed by methanol.  
   
   
       8 . The process of  claim 5 , wherein the 1-methoxymethyl-5,5-diphenylbarbituric acid has a purity greater than 98%.  
   
   
       9 . The process of  claim 7 , wherein the 1-methoxymethyl-5,5-diphenylbarbituric acid has a purity greater than 99%.